My internal speakers work fine. When I plug in headphones, the left side has normal audio for about one second, then becomes barely audible. The right side is barely audible all the time. If I unplug them, and re-plug them, the same exact thing happens. Everything looks good in the sound properties page. I know the headphones work because I tried them in another device.
Any advice?
Assuming that the jack was working fine before, it may be the jack itself. Have you tried other headphones just to determine if the plug is oddly sized which can happen.
Yes, the jack did work fine before, and I tried a second pair of headphones and the same thing happened.
It could be the jack socket is loose on the logic board. If you jiggle the headphone plug while in the socket (gently) from front to back, do you hear scratching or the sound dropping in and out? Have music playing while you try this step.
If it is, then you have a loose connection on the board itself which could be due to stress, dry solder joints, etc. If you are still under warranty or Apple care you can have it repaired.
No, unfortunately that doesn't seem to be the case. It's strange how every time I put it back in with the music already playing, I hear it in the left side briefly and then I can barely hear it at all. It plays loud and clear in one side, then nothing. Also, if the headphones are plugged in with no music playing, when I turn the music on it is very quiet in both sides. It's only when the phones are plugged in and I then turn on the music do I hear it briefly on the left side. Very strange.
I just tried to, but as you suggested, I do not have that option. It only lists "headphones" under the output option.So when you plug in the headphones you hear the music at normal volume i.e. loud enough to be clear, in the left side briefly?
With them plugged in, have you played with all the settings for sound in the pref panel? .e.g change the sound output to something else then back. (if you have that option)
Definitely sounds odd.
I just tried to, but as you suggested, I do not have that option. It only lists "headphones" under the output option.
One thing worth trying, do a PRAM reset for a minimum of 3 'dongs'.
Just in case you're not familiar with that process:
Resetting PRAM and NVRAM
1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.
Repeat this 2 more times so that you have heard the machine startup 3 times. This may well clear the sound problem. Let me know if you have success.
I tried what you suggested, but it didn't work.
Thanks